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Green Roof Technical

What is the difference between an extensive and intensive green roof?

You may have heard of a green roof, but did you know that there is more than one type?  In fact there are many variations and the options are seemingly limitless.  You can put almost anything on your roof from small plants to garden ponds and beehives. We can categorise these roofs into four main types, see more details below.

What is an Extensive Green Roof?

To start with take a look at the most simple family of green roofs; extensive.  These are covered with low growing plants such as evergreen sedums.  From a distance an extensive sedum roof can be mistaken for a grass field.  Besides the visual impact of an extensive green roof, they also provide a natural habitat for birds and insects. 

The main difference with a ANS GrufeKit extensive roof is that it comes in kit-form and is quick and easy to install, not to mention the fact that it is pre-grown and therefore green from the start and does not require irrigation.

Green roof installed at Digby Road

What is a Semi Intensive Green Roof?

If you are looking for a slightly more diverse green roof you may be looking for a semi-intensive green roof.  Typically these roofs will have more soil and some small shrubs as well as the low-growing wildflowers and sedums found on an extensive roof.  A semi-intensive green roof can give rise to a richer ecology with more diverse plant and animal species. It also allows for a formal garden to be installed with paths, grass lawn and flowers or pot plants. 

By using an ANS GrufeKit system as the base of your semi-intensive green roof you will benefit from a strong and flexible roof covering that can be self-installed with its simple clip together modules.  Furthermore, these modules also make maintenance such as finding roof leaks, or moving sections of roof very easy.

Green Roof made of alpines

What is an Intensive Green Roof?

When is a roof not a roof?  It’s no joke; it’s hard to believe that you are actually on a roof with some of the intensive systems that have been installed.  Some characteristics include deep soil (often over 150 mm), any type of plant including trees and often paths or hard surfaces for access and recreation.  Why not get your creative juices flowing and put in some exciting garden features such as bee hives or insect hotels to boost the local ecology, ponds or water features to provide an environment for fish, ducks and amphibians such as frogs and newts.  You don’t even need to stop there you could provide a children’s play area with swings, slides and a sand pit or simply some park benches to sit and enjoy the rooftop view.

While the options for an intensive green roof really are endless, you would do well to consider using an ANS GrufeKit as the base of your roof.  Not only will it provide the strength to support whatever you place on top of it, it also makes maintenance easy.  Each clip together module can be removed individually or in sections to check for leaks or simply to move roof sections around.

A beautiful decking surrounded by living walls

What is a Brown Roof?

The brown roof is so named as it is can be a way of replicating a brownfield site on the roof of a building.  There are a number of options with a brown roof; it can be pre-sown with wildflower seeds to ensure interest during spring and summer.  Alternatively you can simply leave the soil surface to germinate with wind transported local seeds and develop as part of the local ecosystem.  Like a brownfield site you can even recycle building rubble and materials or place specific features to encourage biodiversity such as rotting log piles or small sand dunes.

You can benefit from an ANS GrufeKit brown roof system as the self-install kit is not only quick and easy to lay, but also contains the soil (and wildflower seeds unless otherwise specified) saving the need for earth spreading on the roof.  As with all ANS GrufeKit products, the modular system is brilliant for on-going roof maintenance.

Brown roof in use

What is the difference between an extensive and intensive green roof? Case Studies